This project aims first to elucidate how starch is broken down to glucose in the digestive system of man and secondly to explore aspects of the enzymology of this process as they relate to diet, diabetes and the developing animal. Diagnostic assays dependent on the starch-digesting enzymes may prove useful in characterizing pancreatic disease. In the first part of the project, we will purify, characterize and study the substrate specificities of the several individual enzymes of starch digestion of which the actions are so far incompletely understood. Special attention will be paid to the largely unexplored question of how the complex oligosaccharide products of alpha-amylase action, the alpha-limit dextrins, are further degraded. The search for starch digesting enzymes will be widened beyond the intestine to include the pancreas and stomach. The special enzymology pertaining to the digestion of raw starch will be explored and the metabolic fate of chemically modified starches of the type used in processed foods will be determined. In the second part, the levels of starch degrading enzymes in the digestive system of growing animals will be observed as well as the effects on these enzymes in the mature animal of diet, starvation and diabetes. Finally, alpha-amylase and alpha-glucosidase levels will be determined in serum and urine from patients suffering from pancreatic disease and other diseases that cause hyperamylasemia, with a view to developing improved diagnostic assays for pancreatic disfunction. In these assays, we will employ specific alpha-amylase inhibitors that we have purified from plant sources.